Find all the documentation for downloading your vintage hifi or audiophile Quad on vintageshifi.com, whether it is to use your device or to repair it. You will find these documents in the form of PDF files: Download service manual, audio manuals, hifi manuals, service information, schematics, owner's manuals, brochures, catalogs for amplifiers, pre-amps, power amps, tuners, tape decks, cd players etc...
Looking for more technical elements on a particular model, go to the technical files, to find the equivalent transistors and the list of electrolytic capacitors.